Hello,

1. Please add this code to the Theme Settings > Custom CSS > Global:

body .mega-menu-list .sub-sub-menu li a, .menu-mega-dropdown .sub-sub-menu li a {
    display: block;
    padding: 0;
    font-size: 14px;
    line-height: 14px;
}

Change padding and line-height as per your needs.

2. Find the HTML block which is added to the menu item and set the background image https://wpbakery.com/video-academy/add-row-column-background-wpbakery-page-builder-wordpress/

3. Try to do it by means of an information box https://xtemos.com/docs/woodmart/header-builder/add-edit-builder-elements/

Best Regards